CN104056580B - A kind of fixed fluidized-bed reactor and application thereof - Google Patents

Abstract

The invention discloses a fixed fluidized bed reactor and its application. The reactor includes a top sealing structure, a reactor main body, an outlet pipe (8) and a feed pipe (1) communicating with the reactor. The reactor The main body includes from top to bottom: the settlement section (I), the first reaction section (II-1), the second reaction section (II-2) and the oil agent initial contact section (III), and the horizontal section at the lower end of the settlement section (I). The cross-sectional area is equal to the cross-sectional area of the upper end of the first reaction section (II-1), and the cross-sectional area of the lower end of the first reaction section (II-1) is equal to the cross-sectional area of the upper end of the second reaction section (II-2), The cross-sectional area of the lower end of the second reaction section (II-2) is equal to the cross-sectional area of the upper end of the oil agent initial contact section (III), and the cross-sectional area of the first reaction section (II-1) is from top to bottom The cross-sectional area of the second reaction section (II-2) gradually decreases from top to bottom. The fixed fluidized bed reactor provided by the present invention has the advantages of stable bed linear velocity, sufficient oil agent contact and the like when applied to catalytic cracking of light oil products such as naphtha, and is beneficial to improve product distribution.

Description

A fixed fluidized bed reactor and its application

technical field

The invention relates to a fixed fluidized bed reactor and its application.

Background technique

Catalytic cracking is a technology that cracks petroleum hydrocarbons in the presence of catalysts to produce low-carbon olefins. Due to the advantages of wide source of raw materials, easy adjustment of olefin product structure, low energy consumption and less carbon dioxide emissions, catalytic cracking technology has made great progress in recent years. a faster development. Especially for light oil products such as naphtha catalytic cracking technology is an important technology to optimize the utilization of naphtha resources and improve the economic benefits of refineries. The process development around this technology, the development of catalysts, or the screening of different feedstock oils and catalysts The evaluation is inseparable from the small evaluation device in the laboratory.

At present, the experimental devices used in catalytic cracking mainly include circulating fluidized bed, fixed fluidized bed and fixed bed. The fixed fluidized bed device is widely used because of its simple structure, good operating flexibility, isothermal bed, and high heat transfer efficiency. It is used in the experimental research of catalytic cracking, and the fixed fluidized bed reactor is the core equipment of this type of experimental device.

In the prior art, the structure of a commonly used fixed fluidized bed reactor is shown in FIG. 1 . The reactor is composed of a flange plate, a columnar settling section and a conical reaction section from top to bottom. In addition, the reactor is equipped with feed pipelines, thermocouple sleeves, reaction oil and gas filter tubes and other components. It can be seen from Figure 1 that the feed line, thermocouple sleeve, and filter tube are all fixed on the top of the reactor through flanges, and the feed line is inserted into the reactor along the central axis from top to bottom, and the insertion depth is generally It is more than 1/2 of the vertical height of the reactor. Although the reactor has the characteristics of simple structure and good operating flexibility, due to the limitation of the feeding method, the actual preheating temperature of the raw oil often deviates from the preheating temperature required by the test, and is close to the internal temperature of the reactor, resulting in excessive Thermal cracking results in increased production of dry gas and coke. In addition, the atomization effect of raw oil is not ideal, especially when the fraction above 538 °C in the raw oil is high, the coke yield obtained in the test is much higher than the industrial production data, and the comparability of the test data will be affected.

US6069012 discloses an improved fixed fluidized bed reactor, the structure of which is shown in Figure 2. Both the settling section and the reaction section of the reactor are cylindrical, and the fixed fluidized bed reactor can adjust the reaction time by adjusting the height of the feed nozzle. In addition, a fluidization gas nozzle is added at the bottom of the reactor to improve the fluidization state of the catalyst. Due to the limitation of the linear velocity of the bed, the reactor is only suitable for testing under conventional catalytic cracking reaction conditions.

In addition, CN2512495Y, CN201042664Y, CN202438304U and other patented technologies are partially improved on the basis of the conventional fixed fluidized bed reactor configuration shown in Figure 1 to adapt to different processes. For example, CN201042664Y adopts a similar feed system, adopts a conical reactor, and adds a distribution plate, which to a certain extent improves the disadvantage of fluidization quality degradation at high temperature and high linear velocity.

As another example, CN201064712Y discloses a fixed fluidized bed reactor for experimental research, the structure of which is shown in FIG. 3 . The reactor includes settling section I, reaction section II and oil agent initial contact section III from top to bottom. The reactor mainly improves the configuration of the settling section. Composed of section Ia and cylindrical settling section Ib, it can shorten the coexistence time of reaction intermediate products in the catalyst dilute phase section, and effectively shorten the polycondensation reaction between small molecular olefins.

In summary, the fixed fluidized bed reactors in the prior art are mainly aimed at the conventional catalytic cracking and catalytic cracking of heavy oils, because the catalytic cracking reactions of light oils such as naphtha have high reaction temperature and low catalyst-to-oil ratio. Large, high oil and gas linear velocity, prolific gas production, etc., but when the above-mentioned fixed fluidized bed reactor is used for catalytic cracking, the catalyst distribution in the bed is not uniform under high temperature reaction conditions, and the oil agent is not in sufficient contact, which will affect The final product distribution, so the fixed fluidized bed reactor of the prior art is not suitable for the catalytic cracking reaction temperature of light oil products such as naphtha, high reaction temperature, large agent-oil ratio, high oil-gas linear velocity, prolific gas production, etc. special response needs.

Contents of the invention

In order to solve the above problems, the present invention provides a new fixed fluidized bed reactor and its application.

In order to achieve the above object, the present invention provides a fixed fluidized bed reactor, said fixed fluidized bed reactor comprises a top sealing structure and a reactor main body which are hermetically connected in a detachable manner, and an outlet pipe communicating with the reactor 8 and feed pipe 1, the reactor main body includes from top to bottom: settling section I, reaction section II and oil agent initial contact section III, wherein the reaction section II includes the first reaction section II from top to bottom -1 and the second reaction section II-2, the cross-sectional area of the lower end of the settling section I is equal to the cross-sectional area of the upper end of the first reaction section II-1, and the cross-sectional area of the lower end of the first reaction section II-1 is the same as that of the second reaction section II-1. The cross-sectional area of the upper end of section II-2 is equal, the cross-sectional area of the lower end of the second reaction section II-2 is equal to the cross-sectional area of the upper end of the oil agent initial contact section III, and the cross-sectional area of the first reaction section II-1 The area gradually increases from top to bottom, and the cross-sectional area of the second reaction section II-2 gradually decreases from top to bottom.

The invention also provides the application of the fixed fluidized bed reactor in the catalytic cracking of light oil products, especially naphtha.

The fixed fluidized bed reactor provided by the present invention improves the configuration of the reaction section II, so that when the reactor is applied to the catalytic cracking of light oil products such as naphtha, the linear velocity of the bed layer is stable and the oil It is beneficial to improve the product distribution and increase the yield of the target product due to the characteristics of sufficient contact with the agent.

Other features and advantages of the present invention will be described in detail in the following detailed description.

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the description, together with the following specific embodiments, are used to explain the present invention, but do not constitute a limitation to the present invention. In the attached picture:

Fig. 1 is a kind of structural representation of conventional fixed fluidized bed reactor;

Fig. 2 is the structural representation of a kind of fixed fluidized bed reactor disclosed in US6069012;

Fig. 3 is a structural representation of a fixed fluidized bed reactor disclosed by CN201064712Y;

Fig. 4 is a schematic structural view of a fixed fluidized bed reactor according to a specific embodiment of the present invention.

Explanation of reference signs

1-feed pipe; 2-distribution plate; 3-thermocouple temperature measuring tube; 4-filter tube; 5-lower flange;

6-gasket; 7-filter tube sealing seat; 8-outlet pipe; 9-upper flange; 10-bolt;

Ⅰ-sedimentation section; Ⅱ-reaction section (Ⅱ-1 first reaction section, Ⅱ-2 second reaction section);

Ⅲ-Oil agent initial contact section;

α-the angle of the frustum of the first reaction section Ⅱ-1;

β-The included angle of the frustum of the second reaction stage II-2.

detailed description

Specific embodiments of the present invention will be described in detail below. It should be understood that the specific embodiments described here are only used to illustrate and explain the present invention, and are not intended to limit the present invention.

In the present invention, unless stated otherwise, the top of the reactor refers to the lower surface of the top in the height direction of the reactor, preferably the lower surface of the upper flange 5 . The bottom of the reactor refers to the lower surface of the oil agent initial contact section III in the height direction of the reactor. The opening ratio refers to the ratio of the total area of the sieve holes on the distribution plate 2 (sieve plate) to the area of the sieve plate.

The upper part and the lower part refer to the upper part or the lower part in the height direction of the reactor, based on 1/2 of the reactor height, the lower part is the lower part, and the higher part is the upper part.

According to the present invention, as shown in Figure 4, the fixed fluidized bed reactor includes a top sealing structure and a reactor main body that are hermetically connected in a detachable manner, an outlet pipe 8 and a feed pipe 1 communicated with the reactor, The main body of the reactor includes from top to bottom: settling section I, reaction section II and oil agent initial contact section III, wherein the reaction section II includes the first reaction section II-1 and the second reaction section from top to bottom Ⅱ-2, the cross-sectional area of the lower end of the settlement section I is equal to the cross-sectional area of the upper end of the first reaction section II-1, and the cross-sectional area of the lower end of the first reaction section II-1 is equal to the cross-sectional area of the upper end of the second reaction section II-2. The cross-sectional areas are equal, the cross-sectional area of the lower end of the second reaction section II-2 is equal to the cross-sectional area of the upper end of the oil agent initial contact section III, and the cross-sectional area of the first reaction section II-1 gradually increases from top to bottom Larger, the cross-sectional area of the second reaction section II-2 gradually decreases from top to bottom.

Wherein, said " hermetically passing through the top of the reactor " refers to: the thermocouple temperature measuring tube 3 enters the reactor from the top of the reactor, and the tube wall of the thermocouple temperature measuring tube 3 is sealed with the junction of the reactor top , to prevent the material in the reactor from leaking out of the reactor from the connection between the thermocouple temperature measuring tube 3 and the top of the reactor. Reference can be made to this explanation for "passing through hermetically" described elsewhere below.

In the present invention, by improving the structure of the reaction section II, the reaction section II is designed to be composed of two sections (the reaction section II includes the first reaction section II-1 and the second reaction section II-2 from top to bottom), That is, the cross-sectional area of the reaction section II along the feeding direction first gradually expands and then gradually decreases, so that the fixed-bed reactor can be particularly suitable for processing light oil products mainly composed of saturated hydrocarbons, especially petroleum. Catalytic cracking reaction of naphtha. Mainly manifested in:

(1) The enlarged initial contact section of the oil agent helps to form a uniform catalyst fluidized bed, which reduces the upward movement of the catalyst due to the high linear velocity of oil and gas, and the formation of a dilute phase zone at the bottom of the reactor, improving the oil agent Contact state;

(2) The bottom-up diameter reduction design of the first reaction section II-1 reduces the proportion of the catalyst entrained to the settling section, to a certain extent reduces the occurrence of the secondary reaction of oil and gas in the settling section, and improves the target product. selectivity;

(3) Preferably, in the first reaction section II-1, a frustum-shaped design with a cross-sectional diameter gradually decreasing from bottom to top is adopted, which helps to shorten the residence time of reaction oil and gas in the settling section and increase the yield of target products; Oil and gas, especially light oil (naphtha) raw materials will expand rapidly after entering the reactor, and the dense phase area of the catalyst caused by the high linear velocity of oil and gas will surge to the settling section of the reactor. The contact time of the oil agent is not suitable, and the catalyst Disadvantages such as poor settlement effect;

(4) Optimal optimization of the cone angles of the oil agent initial contact section III and reaction section II can avoid the problem of excessive growth of the bed linear velocity caused by rapid volume expansion after the light oil product contacts and reacts with the catalyst, and maintains the bed layer line speed and stability of operation.

(5) It is preferable that the integrated design of oil agent initial contact section III and reaction section II adopt the same angle to optimize the gas-solid fluidization quality at the connection between the top of contact section III and the bottom of reaction section II, and prevent the occurrence of dead angles at this point.

According to the present invention, in order to avoid the dead angle between the settling section I and the reaction section II in the fixed fluidized bed reactor of the present invention, preferably, the cross-sectional area of the lower end of the settling section I (the bottom of the settling section I) is not less than the first reaction section The cross-sectional area of the upper end of section II-1 (the top of the first reaction section II-1), more preferably the cross-sectional area of the lower end of the settling section I (the bottom of the settling section I) is the same as the cross-sectional area of the upper end of the first reaction section II-1 (the first reaction section The cross-sectional area of the top of II-1) is equal; the cross-sectional area of the lower end of the first reaction section II-1 (the bottom of the first reaction section II-1) is not smaller than the upper end of the second reaction section II-2 (the second reaction section II-1 2 top), more preferably, the cross-sectional area of the lower end of the first reaction section II-1 (the bottom of the first reaction section II-1) is the same as the cross-sectional area of the upper end of the second reaction section II-2 (the second reaction section II-2 top) of the same cross-sectional area; the cross-sectional area of the lower end of the second reaction section II-2 (the bottom of the second reaction section II-2) is not less than the cross-sectional area of the upper end of the oil agent initial contact section III (the top of the oil agent initial contact section III) Cross-sectional area, more preferably, the cross-sectional area of the lower end of the second reaction section II-2 (the bottom of the second reaction section II-2) is equal to the cross-sectional area of the upper end of the oil agent initial contact section III (the top of the oil agent initial contact section III) , so that the catalyst can be well fluidized and settled in the fixed fluidized bed reactor of the present invention.

In the present invention, any fixed fluidized bed reactor meeting the aforementioned requirements can achieve the purpose of the present invention. For the present invention, it is preferable that both the first reaction section II-1 and the second reaction section II-2 are in the shape of a truncated cone.

According to the present invention, in order to further enhance the uniform distribution of the catalyst in the fixed fluidized bed reactor of the present invention and the quality of gas-solid fluidization, preferably, the angle α of the first reaction section II-1 of the frustum of a cone shape Not less than 15°, preferably not less than 26°. The included angle β of the frustoconical second reaction section II-2 does not exceed 30°, preferably does not exceed 18°. In order to further reduce the height of the settling section while controlling excessive thermal cracking, reducing coke and dry gas yields, preferably, the included angle α of the first reaction section II-1 is not less than that of the second reaction section II-1 2 angle β.

In the present invention, the included angle of the circular frustum refers to the angle between a line parallel to the central axis of the circular frustum and the generatrix of the circular frustum.

According to the present invention, in order to make the distribution of the catalyst in the fixed fluidized bed reactor of the present invention more uniform to better realize the purpose of the invention of the present invention, further preferably, the height of the first reaction section II-1 is the same as the The diameter ratio of the cross section at the upper end of the reaction section is 1:1-4, more preferably 1:1.5-2.5. The ratio of the height of the second reaction section II-2 to the diameter of the cross section of the upper end of the reaction section is 1-3.5:1, more preferably 1.4-2:1.

According to the present invention, there is no special requirement for the installation position of the feed pipe 1 on the reactor, and various installation positions of the prior art can realize the purpose of the invention of the present invention, for example, it can be installed in the fixed fluidized reactor of the present invention. The top of the bed reactor (for example, it can pass through the top of the reactor and communicate with the main body of the reactor) can also be installed on the side wall of the fixed fluidized bed reactor. For the present invention, preferably, as shown in FIG. 4 , the feed pipe 1 communicates with the bottom port of the oil agent initial contact section III. The feed pipe 1 is designed to be in communication with the bottom port of the oil agent initial contact section III, and the lower feeding method is adopted. After preheating, the oil gas directly enters the reactor to contact with the catalyst, so that the feed temperature can be controlled more accurately and at the same time reduce The thermal cracking reaction of oil and gas at high temperature is improved, the content of dry gas and coke in the product is reduced, and the product distribution is improved.

The present invention has no special requirements on the installation position of the outlet pipe 8 on the reactor, and various installation positions of the prior art can realize the purpose of the invention of the present invention, for example, it can be installed in the fixed fluidized bed reaction of the present invention. The top of the reactor (for example, it can pass through the top of the reactor body to communicate with the reactor body), or it can be installed on the side wall of the fixed fluidized bed reactor of the present invention. According to the present invention, in order to effectively inhibit the polycondensation of small molecular olefins under catalysis and reduce the height of the settling section, preferably, the outlet pipe 8 is hermetically inserted into the top of the settling section I through the top cover flange 9, more preferably the The outlet pipe 8 is vertically inserted into the top of the settling section I through the top of the reactor in a hermetically sealed manner.

According to the present invention, preferably there are multiple outlet pipes 8, and the multiple outlet pipes 8 are evenly distributed on the reactor main body.

According to the present invention, preferably at least one end of the outlet pipe 8 located in the reactor main body is equipped with a filter pipe 4, so that the catalyst is filtered through the filter pipe 4, and the reaction oil and gas continue to be discharged from the fixed fluidized bed reaction through the outlet pipe 8. outside the device. Wherein, the installation and fixing methods of the filter tube 4 can be carried out by methods known to those skilled in the art. According to a specific embodiment of the present invention, as shown in Figure 4, the filter tube 4 includes The bottom structure at the end of the outlet pipe 8 and the pipe structure arranged on the outer peripheral wall of the part of the outlet pipe 8, and the pipe structure of part of the filter pipe 4 extends upward along the length direction of the outlet pipe 8, and is higher than The upper flange 9 (that is, exposed outside the reactor main body through the top of the reactor), more preferably, the part of the filter tube 4 that is higher than the upper flange 9 has a tube structure through the filter tube The sealing seat 7 is sealed and fixed on the top of the reactor. In order to be suitable for the higher temperature operating conditions of naphtha catalytic cracking, preferably, the filter tube 4 is made of corundum material with good temperature resistance, long service life, good resistance to rapid cooling and rapid heating, and not easy to burst.

According to the present invention, in order to measure the reaction temperature more accurately, the fixed fluidized bed reactor also includes a thermocouple temperature measuring tube 3, and the present invention has no special requirements on the installation position of the thermocouple temperature measuring tube 3 on the reactor , Various installation positions in the prior art can achieve the purpose of the present invention, for example, it can be inserted into the reaction section II through the top of the reactor for measuring the temperature in the reactor. For the present invention, in order to facilitate installation and better monitor the reaction temperature, the thermocouple temperature measuring tube 3 is vertically inserted into the main body of the reactor through the top of the fixed fluidized bed reactor, and extends to The bottom of the second reaction section II-2 inside the reactor main body. Preferably, the thermocouple temperature measuring tube 3 is inserted into the reactor main body along the central axis of the reactor. The insertion depth of the thermocouple temperature measuring tube 3 in the main body of the reactor is a conventional design of this type of reactor in the art, and will not be repeated here.

According to the present invention, in order to further enhance the uniform distribution and fluidized state of the catalyst in the fixed fluidized bed reactor of the present invention, preferably, as shown in Figure 4, the fixed fluidized bed reactor also includes a distribution plate 2. The distribution plate 2 is fixed at the lower end of the thermocouple temperature measuring tube 3 . In this way, the fluidized medium can evenly contact the catalyst countercurrently in the reactor main body through the fluidized medium distribution plate 2, thereby greatly enhancing the fluidized state of the catalyst in the fixed fluidized bed reactor of the present invention. Further preferably, the distribution plate 2 is a sieve plate, and is perpendicular to the direction of the central axis of the fixed fluidized bed reactor, and the openings on the sieve plate are evenly distributed, preferably the sieve plate It is circular, the ratio of the hole diameter of the sieve plate to the inner diameter of the cross-section of the reactor at its height is 0.3-0.9:1, the opening ratio is 5-50%, and the hole diameter is 0.2-3mm.

According to the present invention, as shown in Figure 4, the top sealing structure is a flange sealing structure, the flange sealing structure includes an upper flange 9 and a lower flange 5, and the top of the reactor is an upper Flange 9. And the top of the reactor is sealed with the reactor main body through the upper flange 9 and the lower flange 5, and the outlet pipe 8 for discharging the oil and gas after the reaction and the thermocouple temperature measuring tube 3 for temperature measurement are all fixed on the upper flange 9 and hermetically pass through the upper flange 9 to insert into the interior of the reactor.

According to the present invention, the method of sealing with flanges is well known to those skilled in the art, and the forms and materials of the upper and lower flanges all adopt the conventional design of this type of reactor in the field. According to the present invention, the device adopting the flange sealing method has a simple structure and is convenient for disassembly and modification. Those skilled in the art know that the upper flange 9 and the lower flange 5 can usually be fixed by means of welding or bolting, so as to seal the top of the reactor main body.

According to a specific embodiment of the present invention, preferably, as shown in Figure 4, in order to facilitate the construction of the fixed fluidized bed reactor, the lower flange 5 is installed on the peripheral wall of the top opening of the reactor main body Above, the upper flange 9 is covered on the top of the reactor main body, and the upper flange 9 is bolted to the lower flange 5 through bolts 10 . In addition, under normal circumstances, in order to make the upper flange 9 and the lower flange 5 more closely connected by bolts 10 and to play a buffer role, a There is gasket 6.

More preferably, in order to facilitate better sealing of the reactor body, the lower flange 5 is integrated with the reactor body.

The improvement of the present invention mainly lies in the structure of the reaction section II, therefore, for the structure (including shape (preferably cylindrical), height, etc.) of the settling section I of the fixed fluidized bed reactor, the initial oil contact section III The structure (including shape (preferably inverted conical shape), height, etc.) can adopt the conventional design of this type of reactor in the art. For example, generally speaking, the settling section I of the fixed fluidized bed reactor commonly used in the prior art is in the shape of a truncated cone or a cylinder, and the settling section I of the present invention can also be in the shape of a truncated cone or a cylinder, and the oil agent initial contact section III It can be a conical shape or an inverted conical shape, which can be selected according to needs.

For the present invention, preferably, as shown in Figure 4, the settling section I of the present invention is cylindrical, and the diameter-to-height ratio of the settling section I is 1:1.5-2.5, more preferably 1:1.8-2.2, The height of the settling section I is 31-35% of the vertical distance from the top of the reactor to the bottom of the reactor. The advantages of choosing a cylindrical shape for the settling section and an inverted conical shape for the initial contact section of the oil agent are that it can shorten the residence time of the reaction intermediate product in the settling section I, inhibit the polycondensation reaction of small molecular olefins, and rapidly mix the oil gas and the catalyst in the initial contact section. Good contact improves the accuracy of experimental results.

Preferably, for the present invention, as shown in Figure 4, the height of the reaction section II is 58-62% of the vertical distance from the top of the reactor to the bottom of the reactor.

Preferably, for the present invention, as shown in Figure 4, the oil agent initial contact section III is in an inverted conical shape, and the height of the oil agent initial contact section III is 3% of the vertical distance from the top of the reactor to the bottom of the reactor. -11%. The inventors of the present invention have found that enlarging the cone angles of the oil agent initial contact section III and the reaction section II can avoid the problem of excessive growth of the bed linear velocity caused by the rapid volume expansion after the light oil product and the catalyst are contacted and reacted. The linear velocity of the bed and the stability of operation are maintained. Therefore, preferably, the cone angle of the oil agent initial contact stage III is 20-45°, more preferably 32-40°; the height of the oil agent initial stage III The diameter ratio to the upper end of the initial stage III of the oil agent is 1.21-2.25:1, more preferably 1.37-1.74:1.

Among them, the cone angle refers to the angle between the two generatrices of the conical shaft section.

Referring to Fig. 4, the working process of a fixed fluidized bed reactor in a preferred embodiment of the present invention will be described in detail.

As a preferred embodiment, the structure of the fixed fluidized bed reactor provided by the present invention is shown in Figure 4, and the fixed fluidized bed reactor includes a top sealing structure and a reaction The main body of the reactor includes from top to bottom: settling section I, reaction section II and oil agent initial contact section III, and the reaction section II includes the first reaction section II-1 and the second reaction section II from top to bottom. Section II-2, the cross-sectional area of the lower end of the settlement section I is equal to the cross-sectional area of the upper end of the first reaction section II-1, and the cross-sectional area of the lower end of the first reaction section II-1 is equal to that of the upper end of the second reaction section II-2 The cross-sectional areas are equal, the cross-sectional area of the lower end of the second reaction section II-2 is equal to the cross-sectional area of the upper end of the oil agent initial contact section III, and the first reaction section II-1 and the second reaction section II-2 are both circular frustums shape. The included angle α of the first reaction section II-1 in the shape of a truncated cone is not less than 15°, the included angle β of the second reaction section II-2 in the shape of a truncated cone is not more than 30°, and the first reaction section II The included angle α of -1 is greater than the included angle β of the second reaction stage II-2. The settling section I is in the shape of a cylinder, and the oil agent initial contact section III is in the shape of an inverted cone.

The top sealing structure of the reactor is a flange sealing structure, the flange sealing structure includes an upper flange 9 and a lower flange 5 , and the top of the reactor is an upper flange 9 . Described lower flange 5 is installed on the peripheral wall of the top opening of reactor main body, and described upper flange 9 covers the top of reactor main body, and makes upper flange 9 and lower flange 5 by bolt 10 Bolt connection, and a gasket 6 is arranged between the upper flange 9 and the lower flange 5 . The reactor also includes a thermocouple temperature measuring tube 3, an outlet pipe 8 and a filter tube 4, wherein the thermocouple temperature measuring tube 3 is hermetically passed through the top of the fixed fluidized bed reactor (that is, the upper method The blue plate 9) is inserted vertically (along the direction of the central axis) into the reactor main body, and extends to the bottom of the second reaction section II-2 in the reactor main body. The fixed fluidized bed reactor further includes a distribution plate 2 fixed on the lower end of the thermocouple temperature measuring tube 3 (direction perpendicular to the central axis of the fixed fluidized bed reactor). Three outlet pipes 8 are vertically inserted into the top of the settling section I through the top of the fixed fluidized bed reactor (that is, the upper flange 9 ) and communicate with the reactor. One end of the outlet pipe 8 located in the reactor main body is respectively equipped with three filter pipes 4, and the three filter pipes 4 respectively include the bottom structure at the end of the outlet pipe 8 in the reactor main body and the outlet pipe 8 arranged on this part. The pipe structure on the outer peripheral wall of the filter pipe 4, and the pipe structure of part of the filter pipe 4 extends upward along the length direction of the outlet pipe 8, and is higher than the upper flange 9 (that is, through the top of the reactor exposed to the The outside of the reactor main body), the tube structure of the part of the filter tube 4 that is higher than the upper flange 9 is sealed and fixed on the top of the reactor through the filter tube sealing seat 7 . The feed pipe 1 communicates with the bottom port of the oil agent initial contact section III.

The catalyst is introduced into the fixed fluidized bed reactor under negative pressure through the feed pipe 1, and the fluidized medium (can be one or more mixtures selected from air, water vapor, nitrogen or helium) It also enters the reactor through feed pipe 1 to fluidize the catalyst in the reactor. The preheated hydrocarbon oil raw material is injected into the catalyst bed which has reached the specified temperature through the feed pipe 1, contacts with the catalyst, and undergoes catalytic cracking reaction under specified operating conditions.

In order to improve the flow state of the catalyst, the flow direction and speed of the mixture of the fluidization gas and the catalyst are adjusted through the distribution plate 2 so as to form a uniform catalyst dense-phase bed in the reaction section. During the movement of raw oil gas from bottom to top, after passing through the reaction section II-1, the linear velocity of the gas is further reduced and fully mixed with the catalyst to form a uniformly mixed dense phase area to ensure the contact time required for the catalytic cracking reaction of raw oil gas ;Catalyst particles form back-mixing under the action of reaction section II-2, which is conducive to the uniform mixing of gas and solid, and part of the catalyst is entrained to the settling section. As the linear velocity of the fluidizing gas decreases, most of the catalyst particles return to reaction section II , while the fluidization gas is filtered by the filter 4 and discharged through the outlet pipe 8, and the discharged gas is collected and metered by the subsequent product recovery system.

The reacted catalyst can be stripped with a stripping medium (such as water vapor, nitrogen or helium), and the stripping medium and the reacted oil gas are also filtered through the filter tube 4 and then discharged through the outlet tube 8. Afterwards, oxygen, air and a mixed gas containing oxygen are introduced through the feed pipe 1 to carry out the catalyst burnt regeneration operation. After the regeneration of the catalyst burnt, the reaction of the above steps can be recycled.

Below by embodiment the invention is described in further detail.

Example 1

This example is used to illustrate the fixed fluidized bed reactor provided by the present invention and its application.

Prepare a fixed fluidized bed reactor according to the reactor configuration shown in Figure 4, the reaction section II includes the first reaction section II-1 and the second reaction section II-2 from top to bottom, the horizontal section at the lower end of the settling section I The cross-sectional area is equal to the cross-sectional area of the upper end of the first reaction section II-1, the cross-sectional area of the lower end of the first reaction section II-1 is equal to the cross-sectional area of the upper end of the second reaction section II-2, and the second reaction section II- 2 The cross-sectional area of the lower end is equal to the cross-sectional area of the upper end of the oil agent initial contact section III, and the cross-sectional area of the first reaction section II-1 gradually increases from top to bottom, and the cross-sectional area of the second reaction section II-2 The cross-sectional area decreases gradually from top to bottom.

Both the first reaction section II-1 and the second reaction section II-2 are in the shape of a truncated cone, wherein the included angle α of the first reaction section II-1 in the shape of a truncated cone is 26°; The included angle β of the second reaction section II-2 is 14°; and the included angle α of the first reaction section II-1 is larger than the included angle β of the second reaction section II-2. The ratio of the height of the first reaction section II-1 to the diameter of the cross-section of the upper end of the reaction section is 1:1.5; the ratio of the height of the second reaction section II-2 to the diameter of the cross-section of the upper end of the reaction section is 1.7:1.

The settling section I is cylindrical, the diameter-to-height ratio of the settling section I is 1:1.8, the oil agent initial contact section III is in the shape of an inverted cone, and the oil agent initial contact section III has a cone angle of 40° , the ratio of the height of the initial stage III of the oil agent to the diameter ratio of the cross section of the upper end of the initial stage III of the oil agent is 1.5:1. The height of the settling section I is 31% of the vertical distance from the top of the reactor to the bottom of the reactor; the height of the reaction section II is 58% of the vertical distance from the top of the reactor to the bottom of the reactor; the initial contact of the oil agent The height of section III is 11% of the vertical distance from the top of the reactor to the bottom of the reactor.

The feed pipe 1 communicates with the bottom port of the oil agent initial contact section III.

The thermocouple temperature measuring tube 3 is vertically inserted (along the central axis direction of the reactor) into the reactor main body through the top of the fixed fluidized bed reactor (that is, the upper flange 9) and extend to the bottom of the third reaction section II-3 in the reactor main body; the fixed fluidized bed reactor also includes a distribution plate 2, which is fixed on the thermocouple temperature measuring tube 3 The lower end of the distribution plate 2 is a circular sieve plate and is perpendicular to the central axis of the fixed fluidized bed reactor. The ratio of the diameter of the sieve plate to the inner diameter of the cross-section of the reactor at its height is It is 0.3:1, the opening ratio is 5%, and the hole diameter is 0.2mm.

Three outlet pipes 8 are vertically inserted into the top of the settling section I through the top of the fixed fluidized bed reactor (that is, the upper flange 9 ) and communicate with the reactor. One end of the outlet pipe 8 located in the reactor main body is respectively equipped with three filter pipes 4, and the three filter pipes 4 respectively include the bottom structure at the end of the outlet pipe 8 in the reactor main body and the outlet pipe 8 arranged on this part. The pipe structure on the outer peripheral wall of the filter pipe 4, and the pipe structure of part of the filter pipe 4 extends upward along the length direction of the outlet pipe 8, and is higher than the upper flange 9 (that is, through the top of the reactor exposed to the The outside of the reactor main body), the tube structure of the part of the filter tube 4 that is higher than the upper flange 9 is sealed and fixed on the top of the reactor through the filter tube sealing seat 7 .

The fixed fluidized bed reactor described in this example was used, and the test was carried out referring to the experimental method of a small fixed fluidized bed device (FFB).

The raw material is straight-run naphtha, and the properties of the raw material are shown in Table 1; the catalyst is a catalytic cracking catalyst, and the trade name is CEP-1, and the properties of the catalyst are shown in Table 2.

After the naphtha raw material is preheated, it is injected into the above-mentioned fixed fluidized bed reactor equipped with a CEP-1 catalyst by a feed pump, and the reactor is subjected to catalytic cracking reaction under the conditions shown in Table 3. The composition of the gaseous product is analyzed by online chromatography, and the liquid product is subjected to simulated distillation and analysis by an offline chromatograph. The coke-deposited catalyst is burnt online, and the _CO2 content in the flue gas is measured by the _CO2 online analyzer to obtain the coke production. , and the analysis results are shown in Table 3.

Comparative example 1

In this comparative example, a small fixed fluidized bed unit (FFB) routinely used in the laboratory was used as the reaction equipment.

After the naphtha raw material is preheated, it is injected into the laboratory conventional fixed fluidized bed reactor equipped with CEP-1 catalyst by the feed pump, so that the reactor is carried out catalytic cracking under the conditions shown in Table 3 reaction. The composition of the gaseous product is analyzed by online chromatography, and the liquid product is subjected to simulated distillation and analysis by an offline chromatograph. The coke-deposited catalyst is burnt online, and the _CO2 content in the flue gas is measured by the _CO2 online analyzer to obtain the coke production. , and the analysis results are shown in Table 3.

Table 1

Table 2

table 3

As can be seen from the results of the above table 3, under the same operating conditions, the catalytic cracking reaction of naphtha raw material is carried out, and the product distribution of embodiment 1 is obviously better than that of comparative example 1, which is embodied in: the dry gas and coke of embodiment 1 The output is obviously lower than that of Comparative Example 1, the decrease rate of dry gas is 40.8%, and the decrease rate of coke is 68.2%. The yield of diene in Example 1 was 32.13%, an increase of 8.27 percentage points compared to Comparative Example 1, in which propylene increased significantly.

Example 2

This example is used to illustrate the fixed fluidized bed reactor provided by the present invention and its application.

According to the method of embodiment 1, adopt the fixed fluidized bed reactor described in this embodiment, the straight-run naphtha whose raw material properties are as shown in table 1 is catalyzed under the effect of catalyst properties as shown in table 2 Cracking reaction, and analysis of reaction products, operating conditions and product analysis results are shown in Table 4.

The difference is that the size parameters of each section of the fixed fluidized bed reactor used in this example are different, and the first reaction section II-1 and the second reaction section II-2 of the fixed fluidized bed reactor used in this example are both It is in the shape of a truncated cone, wherein the angle α of the first reaction section II-1 of the truncated shape is 41°; the angle β of the second reaction section II-2 of the truncated shape is 18°; and the first The included angle α of the first reaction section II-1 is greater than the included angle β of the second reaction section II-2. The ratio of the height of the first reaction section II-1 to the diameter of the cross-section of the upper end of the reaction section is 1:2.5; the ratio of the height of the second reaction section II-2 to the diameter of the cross-section of the upper end of the reaction section is 1.8:1.

The settling section I is cylindrical, the diameter-to-height ratio of the settling section I is 1:2.2, the oil agent initial contact section III is in the shape of an inverted cone, and the oil agent initial contact section III has a cone angle of 32° , the diameter ratio of the height of the initial stage III of the oil agent to the cross section of the upper end of the initial stage III of the oil agent is 1.86:1. The height of the settling section I is 35% of the vertical distance from the top of the reactor to the bottom of the reactor; the height of the reaction section II is 62% of the vertical distance from the top of the reactor to the bottom of the reactor; the initial oil contact section III The height is 3% of the vertical distance from the top of the reactor to the bottom of the reactor.

The feed pipe 1 communicates with the bottom port of the oil agent initial contact section III.

The thermocouple temperature measuring tube 3 is vertically inserted (along the central axis direction of the reactor) into the reactor main body through the top of the fixed fluidized bed reactor (that is, the upper flange 9) and extend to the bottom of the third reaction section II-3 in the reactor main body; the fixed fluidized bed reactor also includes a distribution plate 2, which is fixed on the thermocouple temperature measuring tube 3 The lower end of the distribution plate 2 is a circular sieve plate and is perpendicular to the central axis of the fixed fluidized bed reactor. The ratio is 0.9:1, the opening rate is 50%, and the hole diameter is 3mm.

Comparative example 2

In this comparative example, a small fixed fluidized bed unit (FFB) routinely used in the laboratory was used as the reaction equipment.

After the naphtha raw material is preheated, it is injected into the laboratory conventional fixed fluidized bed reactor equipped with CEP-1 catalyst by the feed pump, so that the reactor can carry out naphtha under the conditions shown in Table 3. Catalytic cracking reaction of oil feedstock. The composition of the gaseous product is analyzed by online chromatography, and the liquid product is subjected to simulated distillation and analysis by an offline chromatograph. The coke-deposited catalyst is burnt online, and the _CO2 content in the flue gas is measured by the _CO2 online analyzer to obtain the coke production. , and the analysis results are shown in Table 4.

Table 4

As can be seen from the results of the above table 4, under the same operating conditions, the catalytic cracking reaction of naphtha raw material is carried out, and the product distribution of embodiment 2 is obviously better than that of comparative example 2, which is embodied in: the dry gas and coke of embodiment 2 The output is obviously lower than that of Comparative Example 2, the decrease rate of dry gas is 41.2%, and the decrease rate of coke is 58.2%. The yield of diene in Example 2 was 29.13%, which was 9.54 percentage points higher than that in Comparative Example 2, in which propylene increased significantly.

Example 3

This example is used to illustrate the fixed fluidized bed reactor provided by the present invention and its application.

According to the method of embodiment 1, adopt the fixed fluidized bed reactor described in embodiment 1 to carry out catalytic cracking under the effect of the catalyzer of catalyst property as shown in table 2 to the straight-run naphtha whose raw material properties are as shown in table 1 Reaction, the difference is that only the cone angle and the aspect ratio of the oil agent initial contact section III are changed, the cone angle of the oil agent contact section III is 30°, and the aspect ratio of the oil agent initial contact section III is 1.87: 1, and the reaction product is analyzed, operating conditions and product analysis results are shown in Table 5.

table 5

From the results in Table 5 above, it can be seen that under the condition that other conditions remain unchanged, only the cone angle of the oil agent initial contact section III is adjusted, when the cone angle of the oil agent initial contact section III is optimized and its aspect ratio is limited Compared with Example 3, in Example 1, the yield of dry gas and coke decreased significantly, and the yield of diene increased by 7.31 percentage points.

It can be seen that, adopting the fixed fluidized-bed reactor improved to the configuration of the reaction section of the present invention, the contact time of catalyst and raw material oil gas, catalyst and product is controlled by changing the contact and flow of oil agent and catalyst in the reactor , Control the feed temperature by changing the feeding method, and change the mass transfer and heat transfer effect by improving the fluidization quality, so the product distribution can be improved very well. These advantages cannot be realized in conventional fixed fluidized bed reactors.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention. These simple modifications All belong to the protection scope of the present invention.

In addition, it should be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way if there is no contradiction. The combination method will not be described separately.

In addition, various combinations of different embodiments of the present invention can also be combined arbitrarily, as long as they do not violate the idea of the present invention, they should also be regarded as the disclosed content of the present invention.

Claims (25)

1. a fixed fluidized-bed reactor, described fixed fluidized-bed reactor comprises the top seal structure and reactor body that are tightly connected removably, the outlet (8) be communicated with this reactor and feed pipe (1), described reactor body comprises from top to bottom: settling section (I), conversion zone (II) and finish initial contact section (III), it is characterized in that, described conversion zone (II) comprises the first conversion zone (II-1) and the second conversion zone (II-2) from top to bottom, the cross-sectional area of settling section (I) lower end is equal with the cross-sectional area of the first conversion zone (II-1) upper end, the cross-sectional area of the first conversion zone (II-1) lower end is equal with the cross-sectional area of the second conversion zone (II-2) upper end, the cross-sectional area of the second conversion zone (II-2) lower end is equal with the cross-sectional area of finish initial contact section (III) upper end, and the cross-sectional area of described first conversion zone (II-1) increases from top to bottom gradually, the cross-sectional area of the second conversion zone (II-2) reduces from top to bottom gradually.

2. fixed fluidized-bed reactor according to claim 1, wherein, described first conversion zone (II-1) and the second conversion zone (II-2) are truncated conical shape.

3. reactor according to claim 2, wherein, the angle (α) of first conversion zone (II-1) of described truncated conical shape is not less than 15 °.

4. reactor according to claim 3, wherein, the angle (α) of first conversion zone (II-1) of described truncated conical shape is not less than 26 °.

5. reactor according to claim 2, wherein, the angle (β) of second conversion zone (II-2) of described truncated conical shape is no more than 30 °.

6. reactor according to claim 5, wherein, the angle (β) of second conversion zone (II-2) of described truncated conical shape is no more than 18 °.

7. according to the reactor in claim 3-6 described in any one, wherein, the angle (α) of described first conversion zone (II-1) is not less than the angle (β) of described second conversion zone (II-2).

8. according to the reactor in claim 2-4 described in any one, wherein, the height of the first conversion zone (II-1) and the diameter of the cross section of this conversion zone upper end are than being 1:1-4.

9. reactor according to claim 8, wherein, the height of the first conversion zone (II-1) and the diameter of the cross section of this conversion zone upper end are than being 1:1.5-2.5.

10. the reactor according to claim 2,5 or 6, wherein, the height of the second conversion zone (II-2) and the diameter of the cross section of this conversion zone upper end are than being 1-3.5:1.

11. reactors according to claim 10, wherein, the height of the second conversion zone (II-2) and the diameter of the cross section of this conversion zone upper end are than being 1.4-2:1.

12. reactors according to claim 1, wherein, described finish initial contact section (III) is inverted conical shape, and the cone angle of described finish initial contact section (III) is 20-45 °; The diameter of the height of described finish starting stage (III) and the cross section of this finish starting stage (III) upper end is than being 1.21-2.25:1.

13. reactors according to claim 12, wherein, the cone angle of described finish initial contact section (III) is 32-40 °; The diameter of the height of described finish starting stage (III) and the cross section of this finish starting stage (III) upper end is than being 1.37-1.74:1.

14. reactors according to claim 1,12 or 13, wherein, described feed pipe (1) is communicated with the bottom port of finish initial contact section (III).

15. according to the reactor in claim 1-6 described in any one, wherein, described fixed fluidized-bed reactor also comprises thermocouple temperature measurement pipe (3), described thermocouple temperature measurement pipe (3) is inserted in described reactor body through the plan vertical of described fixed fluidized-bed reactor hermetically, and extends to the bottom of the second conversion zone (II-2) in described reactor body; Described fixed fluidized-bed reactor also comprises distribution grid (2), and this distribution grid (2) is fixed on the lower end of described thermocouple temperature measurement pipe (3).

16. reactors according to claim 15, wherein, described distribution grid (2) is sieve tray, and perpendicular to the central axis of described fixed fluidized-bed reactor, the diameter of described sieve tray is 0.3-0.9:1 with the ratio of the internal diameter of the reactor cross-section of its place height, percent opening is 5-50%, and bore dia is 0.2-3mm.

17. reactors according to claim 15, wherein, described thermocouple temperature measurement pipe (3) is inserted in described reactor body along the central axis of described reactor.

18. reactors according to claim 1, wherein, described outlet (8) is hermetically through the top at top insertion settling section (I) of reactor.

19. reactors according to claim 18, wherein, described outlet (8) has multiple, and this outlet multiple (8) is uniformly distributed.

20. reactors according to claim 1,18 or 19, wherein, the one end being at least positioned at reactor body at described outlet (8) is provided with screen pipe (4).

21. reactors according to claim 1, wherein, described top seal structure is flange plate seal structure, and described flange plate seal structure comprises upper flange plate (9) and lower flange (5), and described reactor head is upper flange plate (9).

22. reactors according to claim 21, wherein, described lower flange (5) is arranged on the open-topped perisporium of reactor body, described upper flange plate (9) covers the top at reactor body, and by bolt (10), upper flange plate (9) is connected with lower flange (5) bolt, and be provided with sealing gasket (6) between upper flange plate (9) and lower flange (5).

23. reactors according to claim 22, wherein, described lower flange (5) and reactor body are integrated.

Fixed fluidized-bed reactor in 24. claim 1-23 described in any one is for the application in light-end products catalytic pyrolysis.

Fixed fluidized-bed reactor in 25. claim 1-23 described in any one is for the application in naphtha catalytic cracking.